Northwest Airlines and Midwest Airlines will begin a combined services agreement for tickets purchased starting on Nov. 3 and travel starting Nov. 17.
The "codesharing" agreement allows Northwest and Midwest flights to share the same code in reservation systems and airport flight displays.
It includes Northwest's Hawaii-bound flights from Seattle, San Francisco and Los Angeles with travel beginning on Midwest Airlines in Milwaukee, Omaha and Kansas City. The Northwest-operated flights will also be identified by the Midwest Airlines two-letter "YX" code.
The codeshare agreement augments an initial partnership, started in May 2006, when the carriers created a joint frequent flyer program, and formalizes a memorandum of understanding the two carriers signed in May 2007.
Northwest parent company, Northwest Airlines Corp., could end up owning Midwest's parent company, Midwest Air Group, which has agreed to sell to private equity firm TPG Capital. Northwest is a passive investor in the deal with TPG.